Managing Latency Introduced by Virtualization

Abstract

A component manages and minimizes latency introduced by virtualization. The virtualization component determines that a currently scheduled guest process has executed functionality responsive to which the virtualization component is to execute a virtualization based operation, wherein the virtualization based operation is one that is not visible to the guest operating system. The virtualization component causes the guest operating system to de-schedule the currently scheduled guest process and schedule at least one separate guest process. The virtualization component then executes the virtualization based operation concurrently with the execution of the at least one separate guest process. Responsive to completing the execution of the virtualization based operation, the virtualization component causes the guest operating system to re-schedule the de-scheduled guest process.

Description

TECHNICAL FIELD[0001]One or more embodiments of this invention pertain generally to virtual computing, and more specifically to managing latency introduced by virtualization.BACKGROUND[0002]Virtualization technologies are becoming prevalent in the market place. At least some of these technologies provide a virtual hardware abstraction to guest operating systems, and allow them to run in virtual machines in a functionally isolated environment on a host computer. Virtualization allows one or more virtual (guest) machines to run on a single physical (host) computer, providing functional and performance isolation for processor, memory, storage, etc.[0003]As is well known in the field of computer science, a virtual machine is an abstraction—a “virtualization”—of an actual physical computer system. FIG. 1 shows one possible arrangement of a computer system (computer system 700) that implements virtualization. As shown inFIG. 1, virtual machine or “guest”200 is installed on a “host platfor...

AI Technical Summary

Problems solved by technology

This interface—which may be referred to generally as “virtualization software” or “virtualization logic”—may include one or more software and / or hardware components and / or layers, possibly including one or more of the software components known in the field of virtual machine technology as “virtual machine monitors” (VMMs), “hypervisors,” or “virtualization kernels.” Because virtualization terminology has evolved over time and has not yet become fully standardized, these terms do not always provide clear distinctions between the software layers and components to which they refer.

Virtualization may also introduce significant delays that may or may not be detectable by a guest OS.

These delays may not be anticipated by the guest OS, because the virtualization based operations that give rise to the delays may not be visible to the guest OS.

If the first VM were then to access the GPPN, it would take a page fault in the processor, and the hypervisor would have to bring the contents back from the swap device.

This process can be quite time consuming.

Unfortunately, the guest cannot make forward progress in the meantime, as the hypervisor and its operations are not visible to the guest.

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